1. Field of the Invention
The present invention relates to a ceramic capacitor.
2. Description of the Related Art
In recent years, the demand for miniaturization and thinning of information terminal devices such as mobile phones and mobile music players is increasing. Associated with this, downsizing is also increasingly required in substrates to be installed in electronic devices and electronic components to be installed in substrates. High density mounting of electronic components to be mounted on a substrate is also increasingly required. In order to further downsize electronic components, a built-in electronic component substrate in which an electronic component is embedded has been developed (e.g., Japanese Patent Application Laid-Open No. 2012-114457). In the built-in electronic component substrate, the electronic component-embedded in the substrate needs to be surely electrically connected to a wiring formed on the substrate.
Further, in a situation in which information amounts of electronic devices are increasing, frequency of usage of electronic devices in a further high-frequency area has increased. Therefore, there is a desire of making it possible to use the built-in electronic component substrate in a high-frequency area by reducing an equivalent series inductance (ESL) of an electronic component built in the built-in electronic component substrate.
For example, Japanese Patent Application Laid-Open No. 2001-155962 and Japanese Patent Application Laid-Open No. 2001-102243 suggest a multi-terminal capacitor such as three-terminal capacitor to reduce ESL. However, the multi-terminal capacitors described in Japanese Patent Application Laid-Open No. 2001-155962 and Japanese Patent Application Laid-Open No. 2001-102243 do not consider embedding in a substrate and electrical connection to wirings formed on the substrate. Therefore, it is difficult to suitably embed the multi-terminal capacitors described in Japanese Patent Application Laid-Open No. 2001-155962 and Japanese Patent Application Laid-Open No. 2001-102243 in a substrate. In other words, multi-terminal capacitors described in Japanese Patent Application Laid-Open No. 2001-155962 and Japanese Patent Application Laid-Open No. 2001-102243 are not suitable for being embedded in a substrate.
In the ceramic capacitor to be built into a substrate, there is a problem that adhesion to a substrate is generally low. When an adhesion force between the ceramic capacitor and a resin constituting a substrate is low, the ceramic capacitor is peeled off from a resin constituting the substrate, and there is a possibility that, due to moisture infiltrating from a peeled portion into the substrate, the reliability of the ceramic capacitor is deteriorated or a joint of the via hole electrode and the external electrode of the ceramic capacitor is ruptured.